다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Metamaterials, or engineered materials with rationally designed, subwavelength-scale building blocks, allow us to control the behavior of physical fields in optical, microwave, radio, acoustic, heat transfer, and other applications with flexibility and performance that are unattainable with naturally available materials. In turn, metasurfaces-planar, ultrathin metamaterials-extend these capabilities even further. Optical metasurfaces offer the fascinating possibility of controlling light with surface-confined, flat components. In the planar photonics concept, it is the reduced dimensionality of the optical metasurfaces that enables new physics and, therefore, leads to functionalities and applications that are distinctly different from those achievable with bulk, multilayer metamaterials. Here, we review the progress in developing optical metasurfaces that has occurred over the past few years with an eye toward the promising future directions in the field.

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Planar Photonics with Metasurfaces

Subwavelength resolution imaging requires high numerical aperture (NA) lenses, which are bulky and expensive. Metasurfaces allow the miniaturization of conventional refractive optics into planar structures. We show that high-aspect-ratio titanium dioxide metasurfaces can be fabricated and designed as metalenses with NA = 0.8. Diffraction-limited focusing is demonstrated at wavelengths of 405, 532, and 660 nm with corresponding efficiencies of 86, 73, and 66%. The metalenses can resolve nanoscale features separated by subwavelength distances and provide magnification as high as 170×, with image qualities comparable to a state-of-the-art commercial objective. Our results firmly establish that metalenses can have widespread applications in laser-based microscopy, imaging, and spectroscopy.

Metalenses at visible wavelengths: Diffraction-limited focusing and subwavelength resolution imaging.

Owing to the tremendous demands for high-resolution pixel-scale thin lenses in displays, we developed a graphene-based ultrathin square subpixel lens (USSL) capable of electrically tuneable focusing (ETF) with a performance competitive with that of a typical mechanical refractive lens. The fringe field due to a voltage bias in the graphene proves that our ETF-USSL can focus light onto a single point regardless of the wavelength of the visible light—by controlling the carriers at the Dirac point using radially patterned graphene layers, the focal length of the planar structure can be adjusted without changing the curvature or position of the lens. A high focusing efficiency of over 60% at a visible wavelength of 405 nm was achieved with a lens thickness of <13 nm, and a change of 19.42% in the focal length with a 9% increase in transmission was exhibited under a driving voltage. This design is first presented as an ETF-USSL that can be controlled in pixel units of flat panel displays for visible light. It can be easily applied as an add-on to high resolution, slim displays and provides a new direction for the application of multifunctional autostereoscopic displays. Graphene-based ultrathin lenses with an electrically tuneable focal length could prove useful for providing displays with autostereoscopic 3D functionality, multiview or privacy protection. Developed by scientists in South Korea, the UK and the US, the lenses are just 13 nm thick and are based on a Fresnel Zone Plate (FZP) design made from a series of concentric rings of graphene on a glass substrate. Consisting of up to 5 layers of graphene that is patterned by focused ion-beam milling, the lenses offer a 60% transmission in the visible region and a focal length of 200–300 µm that can be tuned within ~20% range by applying a DC bias voltage. The applied voltage changes the charge carrier density in the graphene, modifying the topology of the FZP and thus its focusing behaviour.

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Electrically focus-tuneable ultrathin lens for high-resolution square subpixels.

The spin Hall effect of light refers to a spin-dependent transverse splitting of light at a planar interface. Previous demonstrations to enhance the splitting have suffered from exceedingly low efficiency. Achievements of the large splitting with high efficiency have been reported in the microwave, but those in the optical regime remain elusive. Here, an approach to attain the large splitting with high efficiency in the near-infrared is proposed and experimentally demonstrated at 800 nm by using a dielectric metasurface. Modulation of the complex transmission of the metasurface leads to the shifts that reach 10λ along with efficiencies over 70% under two linear polarizations. Our work extends the recent attempts to achieve the large and efficient spin Hall effect of light, which have been limited only to the microwave, to the optical regime. 

/pdf/reaching-the-highest-efficiency-of-spin-hall-effect-of-light-1vg7qpv2.pdf

Reaching the highest efficiency of spin Hall effect of light in the near-infrared using all-dielectric metasurfaces

Switchable diurnal radiative cooling by doped VO 2

The enhancement of the optical spin Hall effect (OSHE) of a transmitted beam has been achieved in a small incident angle of a sub-degree scale The OSHE at a large incident angle can be beneficial in optical applications, such as polarization-dependent sensors and filters, but studies to increase the OSHE at a large incident angle have been elusive in transmission mode We propose a dielectric grating on a metal layer to achieve the grating-induced increase of the OSHE The polarization-dependent transmission and OSHE that reaches several wavelengths are numerically demonstrated We also show the tunability of the operating wavelength and incident angle of the OSHE by changing materials and geometrical parameters

/pdf/diffraction-induced-enhancement-of-optical-spin-hall-effect-4dtka6cnfp.pdf

Diffraction-induced enhancement of optical spin Hall effect in a dielectric grating

Broadband perfect absorbers have been intensively researched for decades because of their near-perfect absorption optical property that can be applied to diverse applications. Unfortunately, achieving large-scale and heat-tolerant absorbers has been remained challenging work because of costly and time-consuming lithography methods and thermolability of materials, respectively. Here, we demonstrate a thermally robust titanium nitride broadband absorber with >95% absorption efficiency in the visible and near-infrared region (400-900 nm). A relatively large-scale (2.5 cm × 2.5 cm) absorber device is fabricated by using a fabrication technique of multiple-patterning colloidal lithography. The optical properties of the absorber are still maintained even after heating at the temperatures >600 ∘C. Such a large-scale, heat-tolerant, and broadband near-perfect absorber will provide further useful applications in solar thermophotovoltaics, stealth, and absorption controlling in high-temperature conditions.

/pdf/multiple-patterning-colloidal-lithography-implemented-43ru6w78wn.pdf

Multiple-patterning colloidal lithography-implemented scalable manufacturing of heat-tolerant titanium nitride broadband absorbers in the visible to near-infrared.

Junsuk Rho

Papers

Electrically focus-tuneable ultrathin lens for high-resolution square subpixels.

Reaching the highest efficiency of spin Hall effect of light in the near-infrared using all-dielectric metasurfaces

Switchable diurnal radiative cooling by doped VO 2

Diffraction-induced enhancement of optical spin Hall effect in a dielectric grating

Multiple-patterning colloidal lithography-implemented scalable manufacturing of heat-tolerant titanium nitride broadband absorbers in the visible to near-infrared.